If one finds a contradiction, then the usual reason is the lack of an essential distinction. In this case most modern discussions seem to share most of the same problems, which I think come largely from the reduction of all causes to efficient causes.
The explanation of the will in randomness is, I agree, both incoherent and contrary to experience - the very last thing choice is about is succumbing to chance (except in rare instances when we can’t decide, and choose instead to toss a coin, whether literally or mentally.)
Neither does non-randomness, in the sense of physical cause and effect, allow choice, because it determines fixed outcomes, making choice illusory - contrary to experience, which tells us every moment that we have options.
Returning to Augustine, simply because he was the first Christian theologian to explore the will in depth, his term was arbitrario libero, which in Englsih appears to have connotations of “arbitrary” randomness, but in fact means “free deliberation.”
In other words, the mind considers all kinds of reasons from logical syllogisms to annoying toothache, and reaches a choice based on, but in experience not absolutely determined by, those factors.
In fact, choice would appear to be linked to ideas once commonplace but sidelined by “the mechanical philosophy” - in this case, a real human power to create final causes (ie purposes), and to determine the efficient means to achieve them. The final causation of the will does not operate in opposition to efficient causes, but it is not determined by them either - rather, in its own sphere, it is a different type of causation.
To an extent this is a spectrum not restrcited to humans, because Joshua’s dog, we hear, makes choices on a rather more limited range of final causes, arguably mostly built into his nature.
The human situation - and here is where I get where Jeremy is coming from - is that decisions can be made by us that widely diverge from given nature. Positively, one can pursue the unnatural, but useful, activities of dividing animals into categories or exploring free-will, joining a political party or becoming a hermit. Christians would argue that that is part of God’s gifting to rule the earth on his behalf.
Negatively, one can choose consciously to go against nature or reason. An origin for that perversity is given in Genesis 3, in the deception of a malevolent creature awakening in Eve the possibility of knowing God, yet disobeying him.
That leads to one of the major determinants of the deliberative will, which is the effect of previous free choices - what the old philosophers called “character”. The character we develop severely constrains the choices that, de eventu, we make - for good or ill. Listening to serpents has the worst effect of all - though to avoid facetiousness, the addictive choice in question was to learn to disobey God before learning how to obey.
That’s turned theological, but maybe that was almost inevitable as soon as I brought creativity and final causation into the matter.